Rock roadway rapid excavation method based on thermal stimulation and cold cracking of ground sound monitoring

Abstract

The application discloses a rock roadway hot-activated cold-cracking rapid tunneling method based on ground sound monitoring. The tunneling method is characterized by the synergistic process of microwave radiation heating, hydraulic fracturing cold cracking and real-time ground sound monitoring, effectively reduces the rock strength, reduces the impact load of the tunneling machine cutter, greatly reduces the wear rate, significantly improves the tunneling efficiency, and significantly reduces the safety risk of underground operation. The ground sound monitoring system realizes real-time control of the internal crack expansion of the rock mass, solves the problem of lack of real-time monitoring means in the traditional auxiliary fracturing method, and ensures the stability and controllability of the weakening effect. By reducing the replacement frequency of vulnerable parts, reducing maintenance costs and improving tunneling efficiency, a new technical path is provided for efficient tunneling of hard rock roadway, which breaks through the technical bottleneck of traditional methods under hard rock conditions, provides a safe, stable and efficient solution for efficient tunneling of hard rock roadway in coal mines, and has wide application prospect.

Description

Technical Field

[0001] This invention relates to the field of rock tunnel excavation technology, specifically to a rapid rock tunnel excavation method based on ground sound monitoring and thermal cracking. Background Technology

[0002] Rock tunnels, as core underground roadways in coal mines, account for 30%-50% of the total tunneling volume. However, most rock tunnels traverse hard rocks such as granite and limestone with compressive strengths as high as 100MPa-200MPa and dense structures, resulting in low efficiency of traditional tunneling methods. To address these issues, blasting tunneling suffers from problems such as high vibration, high risk of flyrock, and the need to wait for the blast smoke to dissipate. Mechanical cutting tools experience resistance of 80kN-120kN, leading to high maintenance costs for vulnerable parts and hindering production progress. Among auxiliary weakening technologies, hydraulic fracturing faces the problem of uneven fracture expansion due to the difficulty of high-pressure water penetration, while static fracturing suffers from high technical costs and long reaction times. Furthermore, auxiliary fracturing methods lack real-time monitoring capabilities, making it impossible to grasp the internal fracture expansion of the rock mass, resulting in unstable weakening effects. Therefore, there is an urgent need to develop efficient, safe, and controllable new technologies for hard rock tunneling. Summary of the Invention

[0003] The present invention aims to at least partially solve one of the technical problems in the related art.

[0004] Therefore, embodiments of the present invention propose a rapid tunneling method for rock tunnels with thermal cracking based on ground sound monitoring.

[0005] The rapid tunneling method for thermally fractured rock tunnels based on ground sound monitoring according to embodiments of the present invention includes the following steps:

[0006] S1: Construct hydraulic fracturing boreholes and deploy sealing devices at the rock tunnel excavation face, and at the same time install ground sound signal receivers in the goaf area to build a real-time monitoring network; S2: Directional heating of the working face rock mass is achieved through a microwave radiation emitter, and the propagation of internal cracks in the rock mass is monitored in real time using a ground acoustic system; S3: When the monitoring results show that the fracture depth has reached the design requirements, microwave heating is stopped, and high-pressure cold water is injected into the heated rock mass through the hydraulic fracturing system to weaken the rock mass by utilizing the synergistic effect of thermal shock fracturing and hydraulic fracturing. S4: During the cold cracking process, continue to monitor the crack propagation through the ground acoustic system to determine whether the crack propagation range meets the standard; S5: After the fracture propagation meets the design requirements, a tunneling machine is used to cut the weakened rock mass.

[0007] In some embodiments, in S1, a hydraulic fracturing borehole with a diameter of 42mm-75mm and a depth of 10m-15m is constructed at the center of the rock tunnel excavation face using a hydraulic drilling rig. The borehole sealer is pushed to the bottom of the borehole and the borehole opening is sealed by injecting high-pressure water. The depth of the hydraulic fracturing borehole is designed to cover the cutting range of the subsequent 3-5 cycles of the tunneling machine.

[0008] In some embodiments, in S1, 3-5 installation holes with a depth of 2m are constructed on the sidewall of the goaf, and the ground sound signal receiver is implanted into the hole and fixed with cement mortar. The receiver is connected to the ground data processing system through a flame-retardant and electromagnetic interference-resistant cable to build a real-time data transmission link of "underground monitoring-ground analysis".

[0009] In some embodiments, in S2, a microwave radiator is installed behind the rock tunnel excavation face. The microwave radiator is connected to the radiation port through a rectangular waveguide. The end of the waveguide is tilted downward at 10°-15° so that the radiated electromagnetic waves cover the entire cross section of the working face at an angle of 20°-60°.

[0010] In some embodiments, a rotating reflector is installed at the end of the waveguide to allow electromagnetic waves to scan within the working surface area to avoid local overheating. The power of the microwave radiator is adjusted according to the rock type, with 150kW-200kW power used for high-hardness granite and 50kW-100kW power used for medium-hardness limestone.

[0011] In some embodiments, in S2, microwave heating raises the temperature of the rock mass to 300°C-800°C. Due to the difference in thermal expansion coefficients, the minerals inside the rock mass generate microcracks and release elastic wave signals. The ground sound monitoring system captures these signals and feeds them back to the control system. If the monitoring results show that the crack depth does not meet the design requirements, the power of the microwave transmitter is adjusted or the heating time is extended.

[0012] In some embodiments, in S3, a water tank with added ice and a hydraulic fracturing pump are connected and started, and cold water is injected into the hydraulic fracturing borehole through a high-pressure water injection pipeline. The high-pressure water enters the initial microcracks generated by microwave heating and expands the cracks through the water wedge effect. At the same time, the cold water comes into contact with the high-temperature rock mass, generating a thermal stress difference, which causes the cracks to expand further.

[0013] In some embodiments, in S4, if the monitoring results show that the fracture expansion range meets the design requirements, hydraulic fracturing is stopped; if the monitoring results show that the fracture does not meet the requirements, cold fracturing is stopped, and the "microwave heating-hydraulic cold fracturing" cycle is repeated after the rock mass temperature returns to room temperature.

[0014] In some embodiments, in S5, a cantilever tunneling machine equipped with a roller cutter is used for cutting, and the cutting path extends from the center of the working face to both sides.

[0015] In some embodiments, the cantilever tunneling machine starts cutting from the center of the working face, taking advantage of the most developed cracks at the center to break the rock, and then expands to both sides to reduce the impact load and wear rate of the tunneling machine cutters.

[0016] This invention presents a rapid rock tunnel excavation method based on ground acoustic monitoring using thermal fracturing. This method abandons traditional blasting methods, avoiding problems such as high vibration, high risk of flyrock, and blasting fumes, thus significantly reducing operational safety risks. Through a synergistic process of "microwave radiation heating + hydraulic fracturing + real-time ground acoustic monitoring," the rock mass strength is effectively reduced, decreasing the impact load on the tunneling machine cutters, significantly reducing wear, and substantially improving excavation efficiency. Simultaneously, it significantly reduces the safety risks of underground operations. The ground acoustic monitoring system enables real-time monitoring of the propagation of internal rock fractures, solving the problem of lacking real-time monitoring in traditional auxiliary fracturing methods, ensuring stable and controllable weakening effects. By reducing the frequency of replacing vulnerable parts, lowering maintenance costs, and improving excavation efficiency, it offers better long-term economic benefits. This invention provides a new technical path for efficient excavation of hard rock tunnels, breaking through the technical bottlenecks of traditional methods under hard rock conditions. It offers a safe, stable, and efficient solution for efficient excavation of hard rock tunnels in coal mines, with broad application prospects. Attached Figure Description

[0017] Figure 1 This is a flowchart of a rapid tunneling method for rock tunnels based on ground sound monitoring according to an embodiment of the present invention.

[0018] Figure 2 This is a schematic diagram of microwave radiation heating in a rock tunnel according to an embodiment of the present invention; Figure 3 This is a schematic diagram of hydraulic fracturing and cold cracking in a rock tunnel according to an embodiment of the present invention; 1. Rock tunnel; 2. Hydraulic fracturing borehole; 3. Sealing device; 4. Goaf; 5. Ground sound signal receiver; 6. Microwave radiation transmitter; 7. Hydraulic fracturing fracture; 8. Thermal shock fracture; 9. Radiated electromagnetic waves; 10. Water tank; 11. Hydraulic fracturing pump; 12. High-pressure water injection pipeline. Detailed Implementation

[0019] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0020] like Figures 1 to 3As shown, the rapid tunneling method for rock tunnels with thermal cooling cracks based on ground sound monitoring according to an embodiment of the present invention includes the following steps: S1: Construct hydraulic fracturing borehole 2 and deploy borehole sealing device 3 at the rock tunnel 1 excavation face, and at the same time install ground sound signal receiver 5 in the goaf 4 to build a real-time monitoring network; S2: Directional heating of the working face rock mass is achieved through microwave radiation emitter 6, and the propagation of internal cracks in the rock mass is monitored in real time using the ground sound system; S3: When the monitoring results show that the fracture depth has reached the design requirements, microwave heating is stopped, and high-pressure cold water is injected into the heated rock mass through the hydraulic fracturing system to weaken the rock mass by utilizing the synergistic effect of thermal shock fracturing and hydraulic fracturing. S4: During the cold cracking process, continue to monitor the crack propagation through the ground acoustic system to determine whether the crack propagation range meets the standard; S5: After the fracture propagation meets the design requirements, a tunneling machine is used to cut the weakened rock mass.

[0021] The rapid rock tunneling method based on ground acoustic monitoring in this invention employs a synergistic process of "microwave radiation heating + hydraulic fracturing + real-time ground acoustic monitoring" during the excavation of rock tunnel 1. First, a microwave heating weakening mechanism is used, where directional microwave radiation heats the rock mass at the working face. The thermal stress generated by the difference in thermal expansion coefficients of different minerals within the rock mass induces micro-cracks, creating conditions for subsequent cold fracturing. Then, a thermal fracturing strengthening mechanism is employed. High-pressure cold water is injected immediately after microwave heating, utilizing the "thermal expansion and contraction" effect to generate contraction stress in the rock mass. Simultaneously, the water wedge effect further expands existing cracks, achieving synergistic weakening of the rock mass. Simultaneously, a ground acoustic monitoring feedback mechanism is used, where a ground acoustic system collects elastic wave signals from within the rock mass in real time, analyzing the depth, density, and propagation speed of the cracks. This provides precise data support for process adjustments, forming a closed-loop control. Finally, after the crack propagation meets design requirements, a tunneling machine is used to cut the weakened rock mass. It should be noted that, as... Figure 3 As shown, the fractures mainly include hydraulic fracturing fractures 7 and thermal shock fractures 8.

[0022] The rapid rock tunneling method based on ground acoustic monitoring, which utilizes thermal fracturing, eliminates the need for traditional blasting methods, avoiding problems such as high vibration, high risk of flyrock, and blasting fumes, thus significantly reducing operational safety risks. Through a synergistic process of "microwave radiation heating + hydraulic fracturing + real-time ground acoustic monitoring," the rock mass strength is effectively reduced, decreasing the impact load on the tunneling machine cutters, significantly reducing wear, and substantially improving tunneling efficiency. Simultaneously, it significantly reduces the safety risks of underground operations. The ground acoustic monitoring system enables real-time monitoring of the propagation of internal rock fractures, solving the problem of lacking real-time monitoring in traditional auxiliary fracturing methods, ensuring stable and controllable weakening effects. By reducing the frequency of replacing vulnerable parts, lowering maintenance costs, and improving tunneling efficiency, it offers better long-term economic benefits. This provides a new technical path for efficient tunneling in hard rock, breaking through the technical bottlenecks of traditional methods under hard rock conditions, and providing a safe, stable, and efficient solution for efficient tunneling in hard rock in coal mines, with broad application prospects.

[0023] In some embodiments, in S1, a hydraulic fracturing borehole 2 with a diameter of 42mm-75mm and a depth of 10m-15m is constructed at the center of the rock tunnel 1 excavation face using a hydraulic drilling rig. The borehole sealer 3 is pushed to the bottom of the borehole and the borehole opening is sealed by injecting high-pressure water. The depth design of the hydraulic fracturing borehole 2 covers the cutting range of the subsequent 3-5 cycles of the tunneling machine.

[0024] like Figure 2 and Figure 3 As shown, by pre-deploying the borehole and sealing device 3, the problem of rock temperature drop caused by prolonged cold cracking construction after microwave radiation heating is effectively avoided. This design ensures the continuity and effectiveness of the thermal cracking process and avoids the adverse effects of heat loss on the weakening effect. The borehole depth covers the cutting range of the subsequent 3-5 cycles of the tunnel boring machine, ensuring that the thermal cracking effect can continuously support the tunneling operation and reducing the need for frequent adjustments to construction parameters. The pre-deployment and subsequent thermal cracking process form a good synergy. Through reasonable spatial and temporal planning, the entire tunneling process is seamlessly connected, improving overall operational efficiency. In some embodiments, in S1, 3-5 installation holes with a depth of 2m are constructed on the sidewall of the goaf 4, and the ground sound signal receiver 5 is implanted into the hole and fixed with cement mortar. The receiver is connected to the ground data processing system through a flame-retardant and electromagnetic interference-resistant cable to build a real-time data transmission link of "underground monitoring-ground analysis".

[0025] The ground acoustic monitoring system, acting as the "eyes" of the thermal fracturing process, provides real-time feedback on fracture propagation. Its core value lies in ensuring the precision of process adjustments, enabling a shift from experience-based judgment to data-driven decision-making. The real-time data collected by the monitoring system provides a scientific basis for adjusting process parameters, forming a complete "monitoring-analysis-adjustment" closed-loop control system through a "downhole monitoring-surface analysis" link. This overcomes the technical bottleneck of traditional auxiliary fracturing methods lacking real-time monitoring capabilities, transforming the fracture propagation process from a "black box" to "transparent," and providing data support for process optimization. Through real-time data feedback, precise control of the thermal fracturing process is achieved, significantly improving the stability and predictability of the weakening effect.

[0026] In some embodiments, in S2, a microwave radiator 6 is installed behind the working face of the rock tunnel 1. The microwave radiator 6 is connected to the radiation port through a rectangular waveguide. The end of the waveguide is tilted downward at 10°-15° so that the radiated electromagnetic wave 9 covers the entire cross-section of the working face at an angle of 20°-60°.

[0027] like Figure 2 As shown, the microwave radiator 6 is installed behind the working face of the rock tunnel 1 and is connected to the radiation port through a rectangular waveguide. The end of the waveguide is tilted downward at 10°-15°, and the radiated electromagnetic waves 9 cover the entire cross section of the working face at an angle of 20°-60°.

[0028] For example, by calculating using trigonometric functions (tan30° × 5 = 2.88m, totaling 5.76m), a 60° radiation angle was determined to perfectly cover the entire cross-section. This precise mathematical calculation ensures the uniformity and comprehensiveness of rock mass heating. If the angle is too small, it will not cover the entire working face, resulting in unheated areas of rock mass and affecting the overall weakening effect. If the angle is too large, energy will be dispersed, heating efficiency will decrease, and energy consumption will increase. A reasonable radiation angle balances coverage and energy efficiency. Through precise geometric calculations and parameter sensitivity analysis, the uniformity and efficiency of microwave heating are ensured, laying a solid foundation for subsequent thermal cracking processes.

[0029] In some embodiments, a rotating reflector is installed at the end of the waveguide to allow electromagnetic waves to scan within the working surface area to avoid local overheating. The power of the microwave radiator 6 is adjusted according to the rock type, with 150kW-200kW power used for high-hardness granite and 50kW-100kW power used for medium-hardness limestone.

[0030] By installing a rotating reflector at the end of the waveguide, electromagnetic waves can scan within the working surface. This design effectively avoids localized overheating and ensures more uniform heating of the rock mass. Dynamic scanning heating solves the problem of uneven heating that may occur with fixed-angle heating. The microwave radiation power is adjusted according to rock type: 150kW-200kW for high-hardness granite and 50kW-100kW for medium-hardness limestone. This differentiated power setting ensures effective weakening while avoiding energy waste. The system can adapt to the weakening needs of rocks of different hardness. Through power adjustment and scanning mechanisms, precise control of the heating process is achieved, optimizing energy utilization efficiency while ensuring effectiveness. In some embodiments, in S2, microwave heating raises the temperature of the rock mass to 300°C-800°C. Due to the difference in thermal expansion coefficients, the minerals inside the rock mass generate microcracks and release elastic wave signals. The ground sound monitoring system captures these signals and feeds them back to the control system. If the monitoring results show that the crack depth does not meet the design requirements, the power of the microwave transmitter is adjusted or the heating time is extended.

[0031] Heating the rock mass to 300℃-800℃ is sufficient to induce differences in the thermal expansion coefficients of minerals. Precise temperature control is a key parameter for effective weakening, directly impacting subsequent cold cracking. The differences in thermal expansion coefficients among different minerals within the rock mass generate uneven thermal stress, leading to microcracks and the release of elastic wave signals. This process fully utilizes the inherent physical properties of the rock material, achieving precise weakening. A ground acoustic system captures the elastic wave signals released during crack formation. Based on the monitoring results, it determines whether the crack depth meets the standard. By adjusting the microwave power or extending the heating time, the process parameters are dynamically optimized, forming a closed-loop control system of "heating-monitoring-adjustment" to ensure the weakening effect meets the requirements.

[0032] In some embodiments, in S3, the water tank 10 with added ice and the hydraulic fracturing pump 11 are connected and started. Cold water is injected into the hydraulic fracturing borehole 2 through the high-pressure water injection pipeline 12. The high-pressure water enters the initial microcracks generated by microwave heating and expands the cracks through the water wedge effect. At the same time, the cold water comes into contact with the high-temperature rock mass and generates a thermal stress difference, which causes the cracks to expand further.

[0033] A water tank 10 with added ice is used to lower the water temperature and enhance the thermal stress difference. A hydraulic fracturing pump 11 provides high-pressure power, and cold water is delivered to the hydraulic fracturing borehole 2 through a high-pressure water injection pipeline 12. The high-pressure water enters the initial microcracks generated by microwave heating, expanding existing fractures through the water wedge effect. The thermal stress difference generated by the contact between the cold water and the high-temperature rock mass leads to further crack expansion. These two effects work together to effectively weaken the rock mass. The water tank 10 with added ice enhances the thermal stress difference, improves the weakening effect, directly utilizes the initial microcracks generated by microwave heating, avoids the fracture expansion process starting from scratch, fully utilizes the physical principle of thermal shock fracturing, and achieves efficient energy utilization. In some embodiments, in S4, if the monitoring results show that the fracture expansion range meets the design requirements, hydraulic fracturing is stopped; if the monitoring results show that the fracture does not meet the requirements, cold fracturing is stopped, and the "microwave heating-hydraulic cold fracturing" cycle is repeated after the rock mass temperature returns to room temperature.

[0034] The ground acoustic system continuously monitors fracture expansion based on whether the fracture propagation range meets design requirements, providing data support for process control. The monitoring results determine whether to continue the cold fracturing process. If the fracture propagation range meets design requirements, hydraulic fracturing is stopped to avoid unnecessary energy consumption. If the fracture does not meet the requirements, cold fracturing is stopped, and the rock mass temperature is allowed to recover to room temperature. The weakening effect is gradually achieved through repeated microwave heating-hydraulic cold fracturing cycles. Process parameters are flexibly adjusted based on actual monitoring results to avoid energy waste. Cyclic treatment ensures the final weakening effect meets requirements, guaranteeing tunneling efficiency. The rock mass temperature is allowed to recover to room temperature to ensure the safety of subsequent operations. In some embodiments, in S5, a cantilever tunneling machine equipped with a roller cutter is used for cutting, and the cutting path extends from the center of the working face to both sides.

[0035] Cantilever tunneling machines equipped with roller cutters are particularly suitable for handling weakened hard rock. Compared to traditional cutting tools, roller cutters offer higher cutting efficiency and lower impact load on fractured rock masses. Cutting begins at the center of the working face and extends outwards in a V-shape or fan-shaped path. This cutting method facilitates stress release, reduces secondary fracturing, and improves cutting efficiency. The cutting path design fully considers the weakened characteristics of the rock mass after thermal cracking. The outward-expanding cutting path from the center promotes uniform stress release, and a well-designed cutting path further enhances overall tunneling efficiency. In some embodiments, the cantilever tunneling machine starts cutting from the center of the working face, taking advantage of the most developed cracks at the center to break the rock, and then expands to both sides to reduce the impact load and wear rate of the tunneling machine cutters.

[0036] After thermal cracking treatment, the center of the working face exhibits the most developed fissures and the lowest rock strength. Starting cutting from the weakest point aligns with the engineering principle of addressing easier issues first, reducing the overall difficulty of rock breaking. The cutting method, extending from the center outwards, effectively reduces the instantaneous impact load on the tunneling machine cutters, preventing direct contact between the cutters and unweakened high-strength rock, significantly extending cutter life. Reduced cutter wear directly decreases equipment maintenance costs and downtime. This cutting method facilitates uniform stress release, reduces localized stress concentration, and the rational cutting sequence further improves overall tunneling efficiency, reduces equipment operating load, and enhances operational safety. In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0037] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0038] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0039] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0040] In this invention, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0041] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A rapid tunneling method for rock tunnels with thermal cooling cracks based on ground sound monitoring, characterized in that, Includes the following steps: S1: Construct hydraulic fracturing boreholes and deploy sealing devices at the rock tunnel excavation face, and at the same time install ground sound signal receivers in the goaf area to build a real-time monitoring network; S2: Directional heating of the working face rock mass is achieved through a microwave radiation emitter, and the propagation of internal cracks in the rock mass is monitored in real time using a ground acoustic system; S3: When the monitoring results show that the fracture depth has reached the design requirements, microwave heating is stopped, and high-pressure cold water is injected into the heated rock mass through the hydraulic fracturing system to weaken the rock mass by utilizing the synergistic effect of thermal shock fracturing and hydraulic fracturing. S4: During the cold cracking process, continue to monitor the crack propagation through the ground acoustic system to determine whether the crack propagation range meets the standard; S5: After the fracture propagation meets the design requirements, a tunneling machine is used to cut the weakened rock mass.

2. The rapid tunneling method for rock tunnels with thermal cooling cracks based on ground sound monitoring according to claim 1, characterized in that, In S1, a hydraulic fracturing borehole with a diameter of 42mm-75mm and a depth of 10m-15m is constructed at the center of the rock tunnel excavation face using a hydraulic drilling rig. The borehole sealer is pushed to the bottom of the borehole and the borehole opening is sealed by injecting high-pressure water. The depth of the hydraulic fracturing borehole is designed to cover the cutting range of the subsequent 3-5 cycles of the tunneling machine.

3. The rapid tunneling method for rock tunnels with thermal cooling cracks based on ground sound monitoring according to claim 1, characterized in that, In S1, 3-5 installation holes with a depth of 2m are constructed on the sidewall of the goaf. The ground sound signal receiver is implanted into the hole and fixed with cement mortar. The receiver is connected to the ground data processing system through a flame-retardant and electromagnetic interference-resistant cable to build a real-time data transmission link of "underground monitoring-ground analysis".

4. The rapid tunneling method for thermally fractured rock tunnels based on ground sound monitoring according to claim 1, characterized in that, In S2, a microwave radiator is installed behind the rock tunnel excavation face. The microwave radiator is connected to the radiation port through a rectangular waveguide. The end of the waveguide is tilted downward at 10°-15° so that the radiated electromagnetic waves cover the entire cross section of the working face at an angle of 20°-60°.

5. The rapid tunneling method for thermally fractured rock tunnels based on ground sound monitoring according to claim 4, characterized in that, A rotating reflector is installed at the end of the waveguide to allow electromagnetic waves to scan within the working surface area, thus avoiding local overheating. The power of the microwave radiation transmitter is adjusted according to the rock type: 150kW-200kW for high-hardness granite and 50kW-100kW for medium-hardness limestone.

6. The rapid tunneling method for rock tunnels with thermal cooling cracks based on ground sound monitoring according to claim 1, characterized in that, In S2, microwave heating raises the rock mass temperature to 300℃-800℃. Due to the difference in thermal expansion coefficients, the minerals inside the rock mass generate microcracks and release elastic wave signals. The ground sound monitoring system captures these signals and feeds them back to the control system. If the monitoring results show that the crack depth does not meet the design requirements, the power of the microwave transmitter is adjusted or the heating time is extended.

7. The rapid tunneling method for rock tunnels with thermal cooling cracks based on ground sound monitoring according to claim 1, characterized in that, In step S3, the water tank containing ice and the hydraulic fracturing pump are connected and started. Cold water is injected into the hydraulic fracturing borehole through the high-pressure water injection pipeline. The high-pressure water enters the initial microcracks generated by microwave heating and expands the cracks through the water wedge effect. At the same time, the cold water comes into contact with the high-temperature rock mass, generating a thermal stress difference, which causes the cracks to expand further.

8. The rapid tunneling method for thermally fractured rock tunnels based on ground sound monitoring according to claim 1, characterized in that, In S4, if the monitoring results show that the fracture expansion range meets the design requirements, hydraulic fracturing is stopped; if the monitoring results show that the fracture does not meet the requirements, cold fracturing is stopped, and the "microwave heating-hydraulic cold fracturing" cycle is repeated after the rock mass temperature returns to room temperature.

9. The rapid tunneling method for thermally fractured rock tunnels based on ground sound monitoring according to claim 1, characterized in that, In S5, a cantilever tunneling machine equipped with a roller cutter is used for cutting, and the cutting path extends from the center of the working face to both sides.

10. The rapid tunneling method for thermally fractured rock tunnels based on ground sound monitoring according to claim 9, characterized in that, The cantilever tunneling machine starts cutting from the center of the working face, taking advantage of the most developed fissures at the center to break the rock, and then expands to both sides to reduce the impact load and wear rate of the tunneling machine's cutting tools.

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